diff options
| -rw-r--r-- | datapath-windows/ovsext/Datapath.c | 456 | ||||
| -rw-r--r-- | datapath-windows/ovsext/Datapath.h | 25 | ||||
| -rw-r--r-- | datapath-windows/ovsext/ovsext.vcxproj | 2 |
3 files changed, 476 insertions, 7 deletions
diff --git a/datapath-windows/ovsext/Datapath.c b/datapath-windows/ovsext/Datapath.c index 3fa56ebcf..3bb2a2a32 100644 --- a/datapath-windows/ovsext/Datapath.c +++ b/datapath-windows/ovsext/Datapath.c @@ -23,7 +23,7 @@ #if defined OVS_USE_NL_INTERFACE && OVS_USE_NL_INTERFACE == 1 #include "precomp.h" -#include "OvsDatapath.h" +#include "Datapath.h" #include "OvsJhash.h" #include "OvsSwitch.h" #include "OvsVport.h" @@ -42,6 +42,153 @@ #define NETLINK_FAMILY_NAME_LEN 48 + +/* + * Netlink messages are grouped by family (aka type), and each family supports + * a set of commands, and can be passed both from kernel -> userspace or + * vice-versa. To call into the kernel, userspace uses a device operation which + * is outside of a netlink message. + * + * Each command results in the invocation of a handler function to implement the + * request functionality. + * + * Expectedly, only certain combinations of (device operation, netlink family, + * command) are valid. + * + * Here, we implement the basic infrastructure to perform validation on the + * incoming message, version checking, and also to invoke the corresponding + * handler to do the heavy-lifting. + */ + +/* + * Handler for a given netlink command. Not all the parameters are used by all + * the handlers. + */ +typedef NTSTATUS (*NetlinkCmdHandler)(PIRP irp, PFILE_OBJECT fileObject, + PVOID inputBuffer, UINT32 inputLength, + PVOID outputBuffer, UINT32 outputLength, + UINT32 *replyLen); + +typedef struct _NETLINK_CMD { + UINT16 cmd; + NetlinkCmdHandler handler; + UINT32 supportedDevOp; /* Supported device operations. */ +} NETLINK_CMD, *PNETLINK_CMD; + +/* A netlink family is a group of commands. */ +typedef struct _NETLINK_FAMILY { + CHAR *name; + UINT32 id; + UINT16 version; + UINT16 maxAttr; + NETLINK_CMD *cmds; /* Array of netlink commands and handlers. */ + UINT16 opsCount; +} NETLINK_FAMILY, *PNETLINK_FAMILY; + +/* + * Device operations to tag netlink commands with. This is a bitmask since it is + * possible that a particular command can be invoked via different device + * operations. + */ +#define OVS_READ_DEV_OP (1 << 0) +#define OVS_WRITE_DEV_OP (1 << 1) +#define OVS_TRANSACTION_DEV_OP (1 << 2) + +/* Handlers for the various netlink commands. */ +static NTSTATUS OvsGetPidCmdHandler(PIRP irp, PFILE_OBJECT fileObject, + PVOID inputBuffer, UINT32 inputLength, + PVOID outputBuffer, UINT32 outputLength, + UINT32 *replyLen); + +/* + * The various netlink families, along with the supported commands. Most of + * these families and commands are part of the openvswitch specification for a + * netlink datapath. In addition, each platform can implement a few families + * and commands as extensions. + */ + +/* Netlink control family: this is a Windows specific family. */ +NETLINK_CMD nlControlFamilyCmdOps[] = { + { OVS_CTRL_CMD_WIN_GET_PID, OvsGetPidCmdHandler, OVS_TRANSACTION_DEV_OP, } +}; + +NETLINK_FAMILY nlControlFamilyOps = { + OVS_WIN_CONTROL_FAMILY, + OVS_WIN_NL_CTRL_FAMILY_ID, + OVS_WIN_CONTROL_VERSION, + OVS_WIN_CONTROL_ATTR_MAX, + nlControlFamilyCmdOps, + ARRAY_SIZE(nlControlFamilyCmdOps) +}; + + + +/* Netlink packet family. */ +/* XXX: Add commands here. */ +NETLINK_FAMILY nlPacketFamilyOps = { + OVS_PACKET_FAMILY, + OVS_WIN_NL_PACKET_FAMILY_ID, + OVS_PACKET_VERSION, + OVS_PACKET_ATTR_MAX, + NULL, /* XXX: placeholder. */ + 0 +}; + +/* Netlink datapath family. */ +/* XXX: Add commands here. */ +NETLINK_FAMILY nlDatapathFamilyOps = { + OVS_DATAPATH_FAMILY, + OVS_WIN_NL_DATAPATH_FAMILY_ID, + OVS_DATAPATH_VERSION, + OVS_DP_ATTR_MAX, + NULL, /* XXX: placeholder. */ + 0 +}; + +/* Netlink vport family. */ +/* XXX: Add commands here. */ +NETLINK_FAMILY nlVportFamilyOps = { + OVS_VPORT_FAMILY, + OVS_WIN_NL_VPORT_FAMILY_ID, + OVS_VPORT_VERSION, + OVS_VPORT_ATTR_MAX, + NULL, /* XXX: placeholder. */ + 0 +}; + +/* Netlink flow family. */ +/* XXX: Add commands here. */ +NETLINK_FAMILY nlFLowFamilyOps = { + OVS_FLOW_FAMILY, + OVS_WIN_NL_FLOW_FAMILY_ID, + OVS_FLOW_VERSION, + OVS_FLOW_ATTR_MAX, + NULL, /* XXX: placeholder. */ + 0 +}; + +static NTSTATUS +MapIrpOutputBuffer(PIRP irp, + UINT32 bufferLength, + UINT32 requiredLength, + PVOID *buffer); +static NTSTATUS +ValidateNetlinkCmd(UINT32 devOp, + POVS_MESSAGE ovsMsg, + NETLINK_FAMILY *nlFamilyOps); +static NTSTATUS +InvokeNetlinkCmdHandler(PIRP irp, + PFILE_OBJECT fileObject, + UINT32 devOp, + POVS_MESSAGE ovsMsg, + NETLINK_FAMILY *nlFamily, + PVOID inputBuffer, + UINT32 inputLength, + PVOID outputBuffer, + UINT32 outputLength, + UINT32 *replyLen); + + /* Handles to the device object for communication with userspace. */ NDIS_HANDLE gOvsDeviceHandle; PDEVICE_OBJECT gOvsDeviceObject; @@ -63,7 +210,11 @@ DRIVER_DISPATCH OvsDeviceControl; #pragma alloc_text(PAGE, OvsDeviceControl) #endif // ALLOC_PRAGMA -#define OVS_MAX_OPEN_INSTANCES 128 +/* + * We might hit this limit easily since userspace opens a netlink descriptor for + * each thread, and at least one descriptor per vport. Revisit this later. + */ +#define OVS_MAX_OPEN_INSTANCES 512 POVS_OPEN_INSTANCE ovsOpenInstanceArray[OVS_MAX_OPEN_INSTANCES]; UINT32 ovsNumberOfOpenInstances; @@ -218,7 +369,8 @@ OvsFindOpenInstance(PFILE_OBJECT fileObject) } NTSTATUS -OvsAddOpenInstance(PFILE_OBJECT fileObject) +OvsAddOpenInstance(POVS_DEVICE_EXTENSION ovsExt, + PFILE_OBJECT fileObject) { POVS_OPEN_INSTANCE instance = (POVS_OPEN_INSTANCE) OvsAllocateMemory(sizeof (OVS_OPEN_INSTANCE)); @@ -247,6 +399,10 @@ OvsAddOpenInstance(PFILE_OBJECT fileObject) ASSERT(i < OVS_MAX_OPEN_INSTANCES); instance->fileObject = fileObject; ASSERT(fileObject->FsContext == NULL); + instance->pid = (UINT32)InterlockedIncrement((LONG volatile *)&ovsExt->pidCount); + if (instance->pid == 0) { + /* XXX: check for rollover. */ + } fileObject->FsContext = instance; OvsReleaseCtrlLock(); return STATUS_SUCCESS; @@ -313,7 +469,7 @@ OvsOpenCloseDevice(PDEVICE_OBJECT deviceObject, switch (irpSp->MajorFunction) { case IRP_MJ_CREATE: - status = OvsAddOpenInstance(fileObject); + status = OvsAddOpenInstance(ovsExt, fileObject); if (STATUS_SUCCESS == status) { InterlockedIncrement((LONG volatile *)&ovsExt->numberOpenInstance); } @@ -374,10 +530,14 @@ OvsDeviceControl(PDEVICE_OBJECT deviceObject, NTSTATUS status = STATUS_SUCCESS; PFILE_OBJECT fileObject; PVOID inputBuffer; - PVOID outputBuffer; + PVOID outputBuffer = NULL; UINT32 inputBufferLen, outputBufferLen; UINT32 code, replyLen = 0; POVS_OPEN_INSTANCE instance; + UINT32 devOp; + OVS_MESSAGE ovsMsgReadOp; + POVS_MESSAGE ovsMsg; + NETLINK_FAMILY *nlFamilyOps; #ifdef DBG POVS_DEVICE_EXTENSION ovsExt = @@ -399,9 +559,293 @@ OvsDeviceControl(PDEVICE_OBJECT deviceObject, code = irpSp->Parameters.DeviceIoControl.IoControlCode; inputBufferLen = irpSp->Parameters.DeviceIoControl.InputBufferLength; outputBufferLen = irpSp->Parameters.DeviceIoControl.OutputBufferLength; - outputBuffer = inputBuffer = irp->AssociatedIrp.SystemBuffer; + inputBuffer = irp->AssociatedIrp.SystemBuffer; + + /* Concurrent netlink operations are not supported. */ + if (InterlockedCompareExchange((LONG volatile *)&instance->inUse, 1, 0)) { + status = STATUS_RESOURCE_IN_USE; + goto done; + } + + /* + * Validate the input/output buffer arguments depending on the type of the + * operation. + */ + switch (code) { + case OVS_IOCTL_TRANSACT: + /* Input buffer is mandatory, output buffer is optional. */ + if (outputBufferLen != 0) { + status = MapIrpOutputBuffer(irp, outputBufferLen, + sizeof *ovsMsg, &outputBuffer); + if (status != STATUS_SUCCESS) { + goto done; + } + ASSERT(outputBuffer); + } + + if (inputBufferLen < sizeof (*ovsMsg)) { + status = STATUS_NDIS_INVALID_LENGTH; + goto done; + } + ovsMsg = inputBuffer; + devOp = OVS_TRANSACTION_DEV_OP; + break; + + case OVS_IOCTL_READ: + /* Output buffer is mandatory. */ + if (outputBufferLen != 0) { + status = MapIrpOutputBuffer(irp, outputBufferLen, + sizeof *ovsMsg, &outputBuffer); + if (status != STATUS_SUCCESS) { + goto done; + } + ASSERT(outputBuffer); + } else { + status = STATUS_NDIS_INVALID_LENGTH; + goto done; + } + + /* + * Operate in the mode that read ioctl is similar to ReadFile(). This + * might change as the userspace code gets implemented. + */ + inputBuffer = NULL; + inputBufferLen = 0; + /* Create an NL message for consumption. */ + ovsMsg = &ovsMsgReadOp; + devOp = OVS_READ_DEV_OP; + + /* + * For implementing read (ioctl or otherwise), we need to store some + * state in the instance to indicate the previous command. The state can + * setup 'ovsMsgReadOp' appropriately. + * + * XXX: Support for that will be added as the userspace code evolves. + */ + status = STATUS_NOT_IMPLEMENTED; + goto done; + + break; + + case OVS_IOCTL_WRITE: + /* Input buffer is mandatory. */ + if (inputBufferLen < sizeof (*ovsMsg)) { + status = STATUS_NDIS_INVALID_LENGTH; + goto done; + } + + ovsMsg = inputBuffer; + devOp = OVS_WRITE_DEV_OP; + break; + + default: + status = STATUS_INVALID_DEVICE_REQUEST; + goto done; + } + + ASSERT(ovsMsg); + switch (ovsMsg->nlMsg.nlmsg_type) { + case OVS_WIN_NL_CTRL_FAMILY_ID: + nlFamilyOps = &nlControlFamilyOps; + break; + case OVS_WIN_NL_PACKET_FAMILY_ID: + case OVS_WIN_NL_DATAPATH_FAMILY_ID: + case OVS_WIN_NL_FLOW_FAMILY_ID: + case OVS_WIN_NL_VPORT_FAMILY_ID: + status = STATUS_NOT_IMPLEMENTED; + goto done; + + default: + status = STATUS_INVALID_PARAMETER; + goto done; + } + + /* + * For read operation, the netlink command has already been validated + * previously. + */ + if (devOp != OVS_READ_DEV_OP) { + status = ValidateNetlinkCmd(devOp, ovsMsg, nlFamilyOps); + if (status != STATUS_SUCCESS) { + goto done; + } + } + + status = InvokeNetlinkCmdHandler(irp, fileObject, devOp, + ovsMsg, nlFamilyOps, + inputBuffer, inputBufferLen, + outputBuffer, outputBufferLen, + &replyLen); + +done: + KeMemoryBarrier(); + instance->inUse = 0; return OvsCompleteIrpRequest(irp, (ULONG_PTR)replyLen, status); } + +/* + * -------------------------------------------------------------------------- + * Function to validate a netlink command. Only certain combinations of + * (device operation, netlink family, command) are valid. + * -------------------------------------------------------------------------- + */ +static NTSTATUS +ValidateNetlinkCmd(UINT32 devOp, + POVS_MESSAGE ovsMsg, + NETLINK_FAMILY *nlFamilyOps) +{ + NTSTATUS status = STATUS_INVALID_PARAMETER; + UINT16 i; + + for (i = 0; i < nlFamilyOps->opsCount; i++) { + if (nlFamilyOps->cmds[i].cmd == ovsMsg->genlMsg.cmd) { + /* Validate if the command is valid for the device operation. */ + if ((devOp & nlFamilyOps->cmds[i].supportedDevOp) == 0) { + status = STATUS_INVALID_PARAMETER; + goto done; + } + + /* Validate the version. */ + if (nlFamilyOps->version > ovsMsg->genlMsg.version) { + status = STATUS_INVALID_PARAMETER; + goto done; + } + + /* Validate the DP for commands where the DP is actually set. */ + if (ovsMsg->genlMsg.cmd != OVS_CTRL_CMD_WIN_GET_PID) { + OvsAcquireCtrlLock(); + if (ovsMsg->ovsHdr.dp_ifindex == (INT)gOvsSwitchContext->dpNo) { + status = STATUS_INVALID_PARAMETER; + OvsReleaseCtrlLock(); + goto done; + } + OvsReleaseCtrlLock(); + } + + status = STATUS_SUCCESS; + break; + } + } + +done: + return status; +} + +/* + * -------------------------------------------------------------------------- + * Function to invoke the netlink command handler. + * -------------------------------------------------------------------------- + */ +static NTSTATUS +InvokeNetlinkCmdHandler(PIRP irp, + PFILE_OBJECT fileObject, + UINT32 devOp, + OVS_MESSAGE *ovsMsg, + NETLINK_FAMILY *nlFamilyOps, + PVOID inputBuffer, + UINT32 inputLength, + PVOID outputBuffer, + UINT32 outputLength, + UINT32 *replyLen) +{ + NTSTATUS status = STATUS_INVALID_PARAMETER; + UINT16 i; + + UNREFERENCED_PARAMETER(devOp); + + for (i = 0; i < nlFamilyOps->opsCount; i++) { + if (nlFamilyOps->cmds[i].cmd == ovsMsg->genlMsg.cmd) { + status = nlFamilyOps->cmds[i].handler(irp, fileObject, + inputBuffer, inputLength, + outputBuffer, outputLength, + replyLen); + break; + } + } + + return status; +} + + +/* + * -------------------------------------------------------------------------- + * Each handle on the device is assigned a unique PID when the handle is + * created. On platforms that support netlink natively, the PID is available + * to userspace when the netlink socket is created. However, without native + * netlink support on Windows, OVS datapath generates the PID and lets the + * userspace query it. + * + * This function implements the query. + * -------------------------------------------------------------------------- + */ +static NTSTATUS +OvsGetPidCmdHandler(PIRP irp, + PFILE_OBJECT fileObject, + PVOID inputBuffer, + UINT32 inputLength, + PVOID outputBuffer, + UINT32 outputLength, + UINT32 *replyLen) +{ + UNREFERENCED_PARAMETER(irp); + UNREFERENCED_PARAMETER(fileObject); + UNREFERENCED_PARAMETER(inputBuffer); + UNREFERENCED_PARAMETER(inputLength); + + POVS_MESSAGE msgIn = (POVS_MESSAGE)inputBuffer; + POVS_MESSAGE msgOut = (POVS_MESSAGE)outputBuffer; + + if (outputLength >= sizeof *msgOut) { + POVS_OPEN_INSTANCE instance = (POVS_OPEN_INSTANCE)fileObject->FsContext; + + RtlZeroMemory(msgOut, sizeof *msgOut); + msgOut->nlMsg.nlmsg_seq = msgIn->nlMsg.nlmsg_seq; + msgOut->nlMsg.nlmsg_pid = instance->pid; + *replyLen = sizeof *msgOut; + /* XXX: We might need to return the DP index as well. */ + } else { + return STATUS_NDIS_INVALID_LENGTH; + } + + return NDIS_STATUS_SUCCESS; +} + + +/* + * -------------------------------------------------------------------------- + * Utility function to map the output buffer in an IRP. The buffer is assumed + * to have been passed down using METHOD_OUT_DIRECT (Direct I/O). + * -------------------------------------------------------------------------- + */ +static NTSTATUS +MapIrpOutputBuffer(PIRP irp, + UINT32 bufferLength, + UINT32 requiredLength, + PVOID *buffer) +{ + ASSERT(irp); + ASSERT(buffer); + ASSERT(bufferLength); + ASSERT(requiredLength); + if (!buffer || !irp || bufferLength == 0 || requiredLength == 0) { + return STATUS_INVALID_PARAMETER; + } + + if (bufferLength < requiredLength) { + return STATUS_NDIS_INVALID_LENGTH; + } + if (irp->MdlAddress == NULL) { + return STATUS_INVALID_PARAMETER; + } + *buffer = MmGetSystemAddressForMdlSafe(irp->MdlAddress, + NormalPagePriority); + if (*buffer == NULL) { + return STATUS_INSUFFICIENT_RESOURCES; + } + + return STATUS_SUCCESS; +} + #endif /* OVS_USE_NL_INTERFACE */ diff --git a/datapath-windows/ovsext/Datapath.h b/datapath-windows/ovsext/Datapath.h index b68010bcf..2bea0fd2c 100644 --- a/datapath-windows/ovsext/Datapath.h +++ b/datapath-windows/ovsext/Datapath.h @@ -42,6 +42,21 @@ typedef struct _OVS_OPEN_INSTANCE { PFILE_OBJECT fileObject; PVOID eventQueue; PVOID packetQueue; + UINT32 pid; + + /* + * On platforms that support netlink natively, there's generally some form of + * serialization between concurrent calls to netlink sockets. However, OVS + * userspace guarantees that a given netlink handle is not concurrently used. + * Despite this, we do want to have some basic checks in the kernel to make + * sure that things don't break if there are concurrent calls. + * + * This is generally not an issue since kernel data structure access should + * be sychronized anyway. Only reason to have this safeguared is to protect + * the state in "state-aware" read calls which rely on previous state. This + * restriction might go away as the userspace code gets implemented. + */ + INT inUse; } OVS_OPEN_INSTANCE, *POVS_OPEN_INSTANCE; NDIS_STATUS OvsCreateDeviceObject(NDIS_HANDLE ovsExtDriverHandle); @@ -52,6 +67,16 @@ POVS_OPEN_INSTANCE OvsGetOpenInstance(PFILE_OBJECT fileObject, NTSTATUS OvsCompleteIrpRequest(PIRP irp, ULONG_PTR infoPtr, NTSTATUS status); +/* + * Structure of any message passed between userspace and kernel. + */ +typedef struct _OVS_MESSAGE { + struct nlmsghdr nlMsg; + struct genlmsghdr genlMsg; + struct ovs_header ovsHdr; + /* Variable length nl_attrs follow. */ +} OVS_MESSAGE, *POVS_MESSAGE; + #endif /* __OVS_DATAPATH_H_ */ #endif /* OVS_USE_NL_INTERFACE */ diff --git a/datapath-windows/ovsext/ovsext.vcxproj b/datapath-windows/ovsext/ovsext.vcxproj index 5ecc81a24..2b3e6fd6d 100644 --- a/datapath-windows/ovsext/ovsext.vcxproj +++ b/datapath-windows/ovsext/ovsext.vcxproj @@ -100,7 +100,7 @@ </PropertyGroup> <ItemDefinitionGroup> <ClCompile> - <PreprocessorDefinitions>%(PreprocessorDefinitions);NDIS_WDM=1;NDIS630=1;OVS_WIN_DP=1;OVS_USE_NL_INTERFACE=0</PreprocessorDefinitions> + <PreprocessorDefinitions>%(PreprocessorDefinitions);NDIS_WDM=1;NDIS630=1;OVS_WIN_DP=1;OVS_USE_NL_INTERFACE=1</PreprocessorDefinitions> </ClCompile> <Midl> <PreprocessorDefinitions>%(PreprocessorDefinitions);NDIS_WDM=1;NDIS630=1</PreprocessorDefinitions> |